DRM, stands for Digital Rights Management in full English name. The characteristics of digital information determines that there must be another unique technology to be applied to strengthen protection of the copyright of the digital audio and video content, said technology is digital rights management technology—DRM (digital rights management).
As shown in FIG. 1, which is a relatively common method for digital rights management, that is one pair of encryption/decryption tool, and can only implement the encryption of one authorization type file, it need different types of file encryption/decryption tools to implement the encryption of different type of the file for different user and apply the different verification process. This method takes great inconvenience to both the DRM users and end-users, because the different encryption/decryption tools need to be installed and used so as to look over different types of encrypted files.
Therefore, how to design an effective method for digital rights management is the study direction of those skilled in the art.